Embodiments of the present invention relate generally to a passive cooling system and more particularly to a multisiphon passive cooling system for a wind turbine.
Many known devices (e.g., generators, rectifiers, inverters and transformers) are used for conversion of electric power. Rectifiers are used for converting alternating current (AC) to direct current (DC) and inverters are used for converting DC current to AC current. Typically, rectifiers and inverters are integrated into full power conversion assemblies (i.e., power converters) used in renewable electric power generation facilities such as solar power generation farms and wind turbine farms. These devices typically generate large amounts of heat during power generation. At least some known power generating devices use a liquid cooling system for cooling the main heat generating components. These liquid cooling systems include an active pump for pumping a working liquid for cooling the power devices, and these systems may also include fans and valves. In such a system, maintaining a flow rate of the working liquid in two or more branches of the liquid cooling system may be problematic due to high resistance to a flow of the working liquid in some branches in comparison to low resistance to the flow of the working liquid in other branches.
A liquid cooling system employing pumps, fans and/or valves is classified as an active system. The term ‘active” referring to the mechanical action performed by the pump to circulate the liquid cooling medium, or the forced airflow by the fan. All active systems require periodic maintenance, and this is critical for system reliability. For example, if a pump fails then the entire cooling system will fail to satisfactorily cool the heat generating components. This is especially problematic for off-shore wind turbines that have limited opportunities for access and maintenance.